A urinary catheter is a tube passed through the urethra or abdominal wall (suprapubic catheter) and into the bladder. Urinary catheters have been in use for the drainage of the bladder for many years. Over 40 years ago the last major development in urinary catheters was introduced, the Foley Catheter. The Foley Catheter has an inflatable balloon at its distal end which allows the catheter to be held within the bladder.
There is a significant major drawback associated with the use of current urinary catheters. Urinary catheters, especially when used on a chronic basis, are associated with a markedly increased incidence of urinary tract infection. Urinary tract infection can take the form of cystitis, pyelonephritis and in the immunocompromised patient, older or particularly debilitated individuals these urinary tract infections can result in the development of systemic sepsis and even death. Identification of the cause or factors associating urinary catheterization and increased rates of urinary tract infections has been illusive. To date, the actual factors causing increased rates of urinary tract infections in patients with urinary catheters has not been identified. Probably as a consequence, the medical products industry has been unable to provide a urinary catheter that is associated with a lower incidence of urinary tract infections.
Length of time of catheterization has been associated with an increasing frequency and severity of urinary tract infections. Therefore, although widely used on a chronic basis, urinary catheters are currently not recommended for chronic use. As yet, no clear evidence has been established to identify the cause or factors relating chronic urinary catheterization to the associated increased rates of urinary tract infection.
As noted above, length of time of catheterization is associated with increased frequency and severity of urinary tract infections. Many patients with long term urinary catheterization develop a state of chronic or relatively constant urinary tract infection. Although the factors responsible for markedly increased rates of urinary tract infection in patients with chronic urinary catheterization have not been identified, clinical observation has shown certain similarities in catheterized patients who develop urinary tract infection. These clinical observations reveal common elements among these chronically catheterized patients when they are hospitalized with acute urinary tract infection. Frequently these patients have the same urinary catheter in place for weeks or even months. The appearance of the urinary catheters withdrawn from these patients is usually remarkably similar: The lumen and inner surfaces of the catheter, is found to be coated with an adherent yellow concentration. This concretion is found to be composed of crystalline urinary deposits, mucus, protien and cellular debris mostly composed of bladder epithelial cells and white blood cells. The concretion also contains significant amounts of bacteria. This concretion or coating on the inner surfaces of the urinary catheter withdrawn from a patient who has had long term urinary catheterization provides an excellent medium for continued bacterial growth, especially in the presence of urine and body heat. This concretion or coating is generally not found on the external surface of the chronis indwelling urinary catheter.
It is proposed that the inner surface or lumen of the urinary catheter provides a location for the adherence and accumulation of this coating. The inner surface of the urinary catheter is less accessable to the body's natural processes for cleansing and resistance to infection. Being less accessable to the body's natural cleansing processes, over time the interior of the urinary catheter becomes coated with the described concretion and provides an excellent medium for bacterial growth and the development of urinary tract infection.
The subject invention is designed to provide a solution to the problem of increased incidence of urinary tract infections in patients with chronis urinary catheterization. The subject design is expected to allow the chronic or long term use of urinary catheterization with decreased rates of urinary tract infection and associated sepsis. This development should have significant impact on the health and longevity of individuals requiring chronic urinary catheterization. In addition, decreased rates of infection will provide shortened hospital stays. The subject invention, by reducing occurence of infection, should provide a reduction of the total number of hospital inpatient days required for individuals with urinary tract infections and associated sepsis. Reduction of urinary tract infection frequency and severity, as well as decreased requirements for antibiotics in patients with urinary catheterization will therefore provide remarkable savings in health care expenditures.
Based on clinical experience with a daily cleansing system for urostomy equipment (Stoma Hygiene System and Process Therefor, patent pending, U.S. Patent and Trademark Office, Ser. No. 731,897), it is proposed that daily cleansing of the inner aspect of a chronic indwelling urinary catheter will prevent accumulation of the described coating. This daily cleansing will therefore eliminate the excellent substrate for the development of urinary tract infection. The subject invention provides a method for the daily cleansing of the inner aspect or lumen of indwelling urinary catheters, without requiring the removal of the urinary catheter from the patient's bladder. The subject method is advantageous for several reasons: the interior of the indwelling urinary catheter can be cleansed without daily removal or changing of the urinary catheter, a process that would be cost prohibitive from the standpoint of equipment and health care personnel costs and inconvenient for the patient as the process of urinary catheterization should be done using a sterile or aspetic technique; and the process of daily removal of a urinary catheter is quite uncomfortable for the patient and potentially damaging to the epithelium of the urethra.
The subject invention proposes a method for the daily cleansing of the inner aspects of chronic indwelling urinary catheters, without requiring removal of the urinary catheter from the patient. It is proposed that the subject method of daily catheter hygiene will eliminate the substrate that facilitates formation of urinary tract infections. The proposed method should therefore markedly reduce the occurence and severity of urinary tract infections in patients with chronic indwelling urinary catheters.